cc: More consistent reasoning about display list memory usage.

cc/playback/display_item_list_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/playback/display_item_list.h"
 
 #include <vector>
 
 #include "cc/output/filter_operation.h"
 #include "cc/output/filter_operations.h"
@@ skipping 266 matching lines @@
   scoped_refptr<DisplayItemList> list_with_caching =
       DisplayItemList::Create(layer_rect, use_cached_picture);
   auto* item2 = list_with_caching->CreateAndAppendItem<DrawingDisplayItem>();
   item2->SetNew(picture);
   list_with_caching->Finalize();
   DrawDisplayList(expected_pixels, layer_rect, list_with_caching);
 
   EXPECT_EQ(0, memcmp(pixels, expected_pixels, 4 * 100 * 100));
 }
 
-TEST(DisplayItemListTest, PictureMemoryUsage) {
+TEST(DisplayItemListTest, ApproximateMemoryUsage) {
   scoped_refptr<DisplayItemList> list;
   size_t memory_usage;
 
   // Make an SkPicture whose size is known.
   gfx::Rect layer_rect(100, 100);
   SkPictureRecorder recorder;
   SkPaint blue_paint;
   blue_paint.setColor(SK_ColorBLUE);
   SkCanvas* canvas = recorder.beginRecording(gfx::RectFToSkRect(layer_rect));
   for (int i = 0; i < 100; i++)
     canvas->drawPaint(blue_paint);
   skia::RefPtr<SkPicture> picture =
       skia::AdoptRef(recorder.endRecordingAsPicture());
   size_t picture_size = SkPictureUtils::ApproximateBytesUsed(picture.get());
   ASSERT_GE(picture_size, 100 * sizeof(SkPaint));
   ASSERT_LE(picture_size, 200 * sizeof(SkPaint));
 
   // Using a cached picture, we should get about the right size.
   list = DisplayItemList::Create(layer_rect, true);
   auto* item = list->CreateAndAppendItem<DrawingDisplayItem>();
   item->SetNew(picture);
   list->Finalize();
-  memory_usage = list->PictureMemoryUsage();
+  memory_usage = list->ApproximateMemoryUsage();
   EXPECT_GE(memory_usage, picture_size);
   EXPECT_LE(memory_usage, 2 * picture_size);
 
   // Using no cached picture, we should still get the right size.
   list = DisplayItemList::Create(layer_rect, false);
   item = list->CreateAndAppendItem<DrawingDisplayItem>();
   item->SetNew(picture);
   list->Finalize();
-  memory_usage = list->PictureMemoryUsage();
+  memory_usage = list->ApproximateMemoryUsage();
   EXPECT_GE(memory_usage, picture_size);
   EXPECT_LE(memory_usage, 2 * picture_size);
 
   // To avoid double counting, we expect zero size to be computed if both the
   // picture and items are retained (currently this only happens due to certain
   // categories being traced).
   DisplayItemListSettings settings;
   settings.use_cached_picture = true;
   list = new DisplayItemList(layer_rect, settings, true);
   item = list->CreateAndAppendItem<DrawingDisplayItem>();
   item->SetNew(picture);
   list->Finalize();
-  memory_usage = list->PictureMemoryUsage();
+  memory_usage = list->ApproximateMemoryUsage();
   EXPECT_EQ(static_cast<size_t>(0), memory_usage);
 }
 
 }  // namespace cc